Push a cart down a supermarket aisle, and you’ll pass a kaleidoscope of color. The use of artificial dyes by foodmakers is up by half since 1990, and it’s not limited to candy. The list of foods made pretty by chemicals now includes pickles, bagels and port wine cheese balls.

“Americans are really turned on by a bright-red strawberry juice, and they think it’s natural,” said Kantha Shelke, co-president of the food research firm Corvus Blue. “Or cheese — cheese is naturally a pale color, but most young kids will not eat cheese unless it’s a bright, almost fluorescent orange.”

Foodmakers have used dyes since ancient times to make food more appealing to the eye. But the practice has so invaded the modern psyche that artificial dyes are being used even on some pet foods. Dogs see limited color, but apparently their owners don’t like buying dull, gray chow.

Now, federal regulators are reexamining artificial ingredients they have long deemed to be safe, prompted by scientific studies suggesting that color additives might be linked to hyperactivity in children and other health effects. On Wednesday, an advisory panel to the Food and Drug Administration will begin a two-day meeting to discuss the science behind artificial dyes and whether the government ought to restrict their use.

Two recent studies sponsored by the British government found that children given foods made with some artificial dyes and a food preservative, sodium benzoate, showed an increase in hyperactivity. The study sampled children in the general population, not just those known to show hyperactive behavior.

The studies remain controversial, with some scientists skeptical about the links that can be drawn.

“At first glance, a study may appear to show an association, but when you consider other important factors that could be responsible for the results, such as gender, maternal education level, pretrial diet and other factors, it becomes impossible to affirm that the change in behavior was due to food colors,” said Keith Ayoob, director of the nutrition clinic at the Rose F. Kennedy Children’s Evaluation and Rehabilitation Center at Albert Einstein College of Medicine.

In 2009, after the studies on hyperactivity, the British government urged foodmakers to stop using six dyes. The European Parliament required foods containing the tested dyes to carry a label warning that products “may have an adverse effect on activity and attention in children.” The government continues to allow the use of several other artificial dyes.

To avoid warning labels on their products in Europe, many foodmakers — including U.S.-based companies such as Kellogg and Mars International — replaced the six dyes with other dyes, including some natural ones made from fruits and vegetables.

“Companies in Europe are managing perfectly well — people get used to a slightly different color,” said Michael Jacobson, executive director of Center for Science in the Public Interest, which has petitioned the FDA to ban artificial dyes and, as a first step, require a warning label.

The Center for Science in the Public Interest points to studies suggesting that some of the dyes are also suspected carcinogens.

In 1990, the FDA banned Red No. 3 in cosmetics, medicines and some other products because it was linked to cancer in mice but permitted its continued use in foods.

Food industry officials say artificial dyes are safe and contend that the British studies and others are inconclusive. Manufacturers also note that the dyes are heavily regulated by the FDA, which requires approval before they can be used commercially, unlike many other ingredients used in foods.

“All of the major safety bodies globally have reviewed the available science and have determined that there is no demonstrable link between artificial food colors and hyperactivity among children,” said statement from the Grocery Manufacturers Association, which represents foodmakers, packagers and retailers.

Still, some U.S. companies are beginning to make the switch away from artificial dyes, driven in part by consumer demands for healthier food.

Frito-Lay is promoting its decision to get rid of artificial colors and flavors in more than 60 of its snack products, substituting ingredients such as beet juice and carrots for Red No. 40, one of the artificial dyes.

“We’re always looking for new ways to give consumers what they’re looking for, which includes providing a wider range of products made with natural ingredients,” said Jeff Dahncke, a spokesman for Pepsico, which owns Frito-Lay. But the company said it has no plans to mess with the chemically enhanced orange of its Doritos or Cheetos, two of its top-selling brands.

In a signal of where the food coloring industry is headed, one major color supplier, Sensient Colors, announced last year that it was spending $16 million to create the largest natural color manufacturing plant in North America. “The trend towards natural colors is accelerating, and this new manufacturing plant will further promote the conversion to natural colors by large food and beverage manufacturers,” Kenneth P. Manning, chairman and chief executive of Sensient Technologies, said at the time.

In this country, the use of dyes took off with the popularity of processed foods after World War II , said Shelke, the food scientist.

Manufacturers originally made processed foods for the military, Shelke said, and after the war, they turned their sights on the consumer market. But housewives buying products for their families were more discerning than soldiers, she said. “The manufacturers wanted to make sure the food would look good,” she said.

“They made tomato juice and realized that it turned brown,” Shelke said. “So the first thing they did was to put color in it.”

Natural colors tend to fade over time and can be inconsistent, so the industry developed chemical dyes that were stable. But their overuse, she said, “has distorted the American concept of what a food looks like.”

Lyndsey Layton has been covering national education since 2011, writing about everything from parent trigger laws to poverty’s impact on education to the shifting politics of school reform.

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